These authors contributed equally to the study.
Loss of nuclear TDP-43 in amyotrophic lateral sclerosis (ALS) causes altered expression of splicing machinery and widespread dysregulation of RNA splicing in motor neurones
Version of Record online: 25 SEP 2014
© 2014 British Neuropathological Society
Neuropathology and Applied Neurobiology
Volume 40, Issue 6, pages 670–685, October 2014
How to Cite
Highley, J. R., Kirby, J., Jansweijer, J. A., Webb, P. S., Hewamadduma, C. A., Heath, P. R., Higginbottom, A., Raman, R., Ferraiuolo, L., Cooper-Knock, J., McDermott, C. J., Wharton, S. B., Shaw, P. J. and Ince, P. G. (2014), Loss of nuclear TDP-43 in amyotrophic lateral sclerosis (ALS) causes altered expression of splicing machinery and widespread dysregulation of RNA splicing in motor neurones. Neuropathology and Applied Neurobiology, 40: 670–685. doi: 10.1111/nan.12148
- Issue online: 25 SEP 2014
- Version of Record online: 25 SEP 2014
- Accepted manuscript online: 18 APR 2014 03:14AM EST
- Manuscript Accepted: 4 APR 2014
- Manuscript Received: 6 JAN 2014
- a Motor Neurone Disease Association/Medical Research Council Lady Edith Wolfson Fellowship. Grant Number: G0800380/1
- a Medical Research Council Clinical Training Fellowship
- a Wellcome Trust neuroscience programme award
- European Union Joint Programme–Neurodegenerative Disease Research (JPND)
- Sampling and biomarker OPtimization and Harmonization In ALS and other motor neurone diseases (SOPHIA)
- United Kingdom, Medical Research Council (MRC)
- European Community's Seventh Framework Programme. Grant Numbers: FP7/2007-2013, 259867
- Motor Neurone Disease Association
- a MND Association/MRC Lady Edith Wolfson Fellowship award. Grant Number: MR/K003771/1
- amyotrophic lateral sclerosis;
- post mortem;
Loss of nuclear TDP-43 characterizes sporadic and most familial forms of amyotrophic lateral sclerosis (ALS). TDP-43 (encoded by TARDBP) has multiple roles in RNA processing. We aimed to determine whether (1) RNA splicing dysregulation is present in lower motor neurones in ALS and in a motor neurone-like cell model; and (2) TARDBP mutations (mtTARDBP) are associated with aberrant RNA splicing using patient-derived fibroblasts.
Affymetrix exon arrays were used to study mRNA expression and splicing in lower motor neurones obtained by laser capture microdissection of autopsy tissue from individuals with sporadic ALS and TDP-43 proteinopathy. Findings were confirmed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and in NSC34 motor neuronal cells following shRNA-mediated TDP-43 depletion. Exon arrays and immunohistochemistry were used to study mRNA splicing and TDP-43 expression in fibroblasts from patients with mtTARDBP-associated, sporadic and mutant SOD1-associated ALS.
We found altered expression of spliceosome components in motor neurones and widespread aberrations of mRNA splicing that specifically affected genes involved in ribonucleotide binding. This was confirmed in TDP-43-depleted NSC34 cells. Fibroblasts with mtTARDBP showed loss of nuclear TDP-43 protein and demonstrated similar changes in splicing and gene expression, which were not present in fibroblasts from patients with sporadic or SOD1-related ALS.
Loss of nuclear TDP-43 is associated with RNA processing abnormalities in ALS motor neurones, patient-derived cells with mtTARDBP, and following artificial TDP-43 depletion, suggesting that splicing dysregulation directly contributes to disease pathogenesis. Key functional pathways affected include those central to RNA metabolism.